Alert archive / New York / Mesoscale Discussions in 2021

Mesoscale Discussion 1192

July 8, 2021Berkshire County, Hampden County, Hampshire County, Massachusetts; 12 counties in New York

The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2021, 12:00 AM EDT for Berkshire County, Hampden County, Hampshire County, Massachusetts; 12 counties in New York. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Jul 8, 2021, 12:00 AM EDT (04:00 UTC)
Expired
Jul 8, 2021, 1:00 AM EDT
In force
60 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Berkshire County, MA, Hampden County, MA, Hampshire County, MA, Albany County, NY, Columbia County, NY, Dutchess County, NY, Greene County, NY, Orange County, NY, Putnam County, NY, Rockland County, NY, Schoharie County, NY, Suffolk County, NY, Sullivan County, NY, Ulster County, NY, Westchester County, NY

The radar

The Brookhaven radar (KOKX), 106 km from the middle of the area, began a volume at 04:00 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 4.0 hours before the alert went out and 106 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2021-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1805 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2021-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1805 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1235 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted.

483 
ACUS11 KWNS 080401
SWOMCD
SPC MCD 080400 
RIZ000-CTZ000-NYZ000-MAZ000-080500-

Mesoscale Discussion 1192
NWS Storm Prediction Center Norman OK
1100 PM CDT Wed Jul 07 2021

Areas affected...Southeast New York...Southern New England

Concerning...Severe potential...Watch unlikely 

Valid 080400Z - 080500Z

Probability of Watch Issuance...20 percent

SUMMARY...The wind-damage threat currently located near the western
edge of WW 344 is expected to continue for another hour. However,
the threat should become more isolated as the line moves eastward
across southeast New York. It is unlikely that WW 344 will need to
be extended further in time beyond the 05Z expiration time.

DISCUSSION...The latest radar imagery from Albany, New York shows a
well-developed line segment, located in the western part of the
Hudson River Valley. The line is near a quasi-stationary front with
surface dewpoints along the boundary around 70 F. The line is
located along the northern edge of a pocket of moderate instability.
MLCAPE is estimated by the RAP near 2000 J/kg over eastern
Pennsylvania and northern New Jersey. The instability will help the
line to remain organized for another hour or so as the cold pool
moves eastward. However, cooling surface temperatures will likely
result in a gradual downtrend of the severe threat.

..Broyles.. 07/08/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BOX...OKX...ALY...BGM...

LAT...LON   40617241 40967383 41277442 41507478 42337484 42697466
            42677361 42567280 41407182 40617241

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 1:44 PM EDTMesoscale DiscussionSPC3 hr
Jul 8, 2:09 PM EDTSevere Thunderstorm WatchSPCGreater Bridgeport Planning Region, Capitol Planning Region, Northwest Hills Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region and 1 more7 hr
Jul 8, 4:36 PM EDTMesoscale DiscussionSPC114 min
Jul 8, 1:31 PM EDTMesoscale DiscussionSPCCattaraugus, Chautauqua, Erie, Wyoming2 hr

Nearby

Mesoscale Discussions in New York, 2021Mesoscale Discussions in Connecticut, 2021Mesoscale Discussions in Massachusetts, 2021Every mesoscale discussion in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.